A Mike Pollitt own goal and a Luis Garcia effort rounded off the rout after an ecstatic Anfield had witnessed Crouch net in the first half with a lovely lob over the keeper - as they condemned their north-west rivals to a third Premiership defeat in a row.
After a pair of early Wigan corners, a confident Liverpool, buoyed by Steven Gerrard's influence in the centre of midfield, spurned a fine chance to take the lead on five minutes.
The skipper sprayed the ball wide to Garcia who whipped in a deep cross to Harry Kewell who forced a decent save from Pollitt.
In a fast-flowing opening, the enthusiastic visitors seemed up to the task, urged on by a boisterous travelling army that were determined to enjoy their first ever league visit to Anfield.
Paul Jewell made nine changes to the second-string team which knocked Newcastle out of the Carling Cup in midweek.
But his side fell behind in the 19th minute when Crouch's 25-yard drive took a huge deflection off Arjan De Zeeuw and was dropped into the net by Pollitt.
Crouch was officially up and running five minutes before the break. He was sent clear by Steve Finnan before executing a tidy lob over Pollitt after former Liverpool star Stephane Henchoz had played the Reds striker onside.
Kewell, Gerrard and Sami Hyypia all missed fine chances for Liverpool before the break as the Reds shifted up a gear or two.
A headed effort from De Zeeuw, which just cleared the bar, was the best Wigan could offer in reply. The veteran defender seemed to injure himself in the process and was replaced by Matt Jackson ten minutes before the break.
Wigan came out all guns blazing in the second half, and a powerful run from Jason Roberts earned him a shooting chance, which was snuffed out by Hyypia before Graham Kavanagh blasted just over from the corner.
Liverpool responded well through Fernando Morientes who hit the bar with a fine header as the Reds continued to dominate.
Jimmy Bullard had the visitors' first effort on target well saved by Jose Reina, but as Jewell's men stormed forward looking for a route back into the game, gaps opened up. It was a gamble they needed to take.
Henri Camara had a penalty appeal turned down before the gamble ended in tears when Garcia deflected Morientes' header home with 20 minutes to go.
Crouch was substituted to a hero's ovation before his Spanish strike partner Morientes spurned yet another chance.
As Liverpool continued to surge forward, two messages were sent out to the rest of the Premiership - the European champions are looking like serious title contenders and the Wigan bubble may have finally burst.
MAN OF THE MATCH: Peter Crouch (Liverpool) - Finally broke his duck but once again proved his game is about more than just scoring goals. Led the line well and showed enough confidence to suggest more goals will now start to flow.